newlib-cygwin/newlib/libc/stdio64/fsetpos64.c

67 lines
1.5 KiB
C

/*
FUNCTION
<<fsetpos64>>---restore position of a large stream or file
INDEX
fsetpos64
INDEX
_fsetpos64_r
SYNOPSIS
#include <stdio.h>
int fsetpos64(FILE *<[fp]>, const _fpos64_t *<[pos]>);
int _fsetpos64_r(struct _reent *<[ptr]>, FILE *<[fp]>,
const _fpos64_t *<[pos]>);
DESCRIPTION
Objects of type <<FILE>> can have a ``position'' that records how much
of the file your program has already read. Many of the <<stdio>> functions
depend on this position, and many change it as a side effect.
You can use <<fsetpos64>> to return the large file identified by <[fp]> to a
previous position <<*<[pos]>>> (after first recording it with <<fgetpos64>>).
See <<fseeko64>> for a similar facility.
RETURNS
<<fgetpos64>> returns <<0>> when successful. If <<fgetpos64>> fails, the
result is <<1>>. The reason for failure is indicated in <<errno>>:
either <<ESPIPE>> (the stream identified by <[fp]> doesn't support
64-bit repositioning) or <<EINVAL>> (invalid file position).
PORTABILITY
<<fsetpos64>> is a glibc extension.
Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
<<lseek64>>, <<read>>, <<sbrk>>, <<write>>.
*/
#include <stdio.h>
#ifdef __LARGE64_FILES
int
_fsetpos64_r (struct _reent *ptr,
FILE * iop,
const _fpos64_t * pos)
{
int x = _fseeko64_r (ptr, iop, (_off64_t)(*pos), SEEK_SET);
if (x != 0)
return 1;
return 0;
}
#ifndef _REENT_ONLY
int
fsetpos64 (FILE * iop,
const _fpos64_t * pos)
{
return _fsetpos64_r (_REENT, iop, pos);
}
#endif /* !_REENT_ONLY */
#endif /* __LARGE64_FILES */